基于WRF模式的成都地区边界层污染气象特征研究

根据2013年成都地区的空气质量资料,对该地区的空气质量状况进行简要分析;并利用NCEP再分析资料,基于WRF模式对成都地区污染天气和清洁天气背景下的边界层气象特征进行模拟。结果表明:(1)成都地区冬季空气质量最差,春季和秋季次之,夏季最好。(2)WRF模式的模拟结果与实际观测结果基本一致。(3)无论是冬季还是夏季,成都地区均以偏北风为主,夏季风速明显大于冬季;随高度的增加,冬季风速逐渐增大,气流运动非常弱,夏季风速先增大后减小,气流以上升运动为主。(4)无论冬季还是夏季,西北部地面气温低,东南部地面气温高,且在成都市区附近均有一个高值中心,夏季气温高于冬季。(5)从边界层高度来看,西部明显低于东部,冬季和夏季在成都市区附近有一个高值中心,夏季显著高于冬季。     

廊坊市“突发”空气重污染的低层风场对比分析

利用2013~2015年廊坊市空气污染资料、MICAPS气象资料、廊坊气象观测站自动站资料,应用数理统计、天气学等方法对廊坊市86次空气重污染前后的低层风场进行了对比分析。结果表明:(1)廊坊市“突发”空气重污染时,因污染程度变化的差异可分为5个等级,其中3级转6级AQI值变化最大,平均变化值达227,4级转5级偏南风至偏西风均为75;(2)“突发”空气重污染过程中,地面风向风速均有明显变化,偏北风控制时间长比例下降,静风、偏南风(SW/SSW/WSW/W)、偏东风(E/ENE/ESE/SE)时间长比例增加;除4级转5级外,地面平均风速均有不同程度下降,以2级转5级下降幅度最大,平均达0.6m/s·d;(3)空气重污染前,1000hPa、925hPa以及850hPa高空以西北风或偏西风为主,空气重污染时,各层风向转为以西南、东南或偏东风控制为主,且常见风的辐合场形成。在三层大气风场风向变化不一致的条件下,以1000hPa风场风向的变化为参考点;(4)在“突发”空气重污染过程中,850hPa、925hPa、1000hPa有北风风速减小、南风风速增加的变化特征,且空气质量的等级变化越大、污染程度越重,大气风场的垂直变化越深厚。     

茫崖地区风资源观测结果初步分析

文章利用设在茫崖(茫崖行委)、黄瓜梁两个测风塔站10m高度处短期风自记资料,经过超短序列订正公式进行订正延长后,对其风向、风速特征进行了初步分析.结果表明:两个测点中,黄瓜梁测点以西(W)风为主,频率为20％;茫崖行委测点以偏北(NNW、NNE)风为主,频率分别为15％和42％.风速1日中10时以后风速逐渐增大,午后至傍晚大约17 ～20时出现日最大值,是风能利用的最佳时间段.两测点年平均风速黄瓜梁为3.5m/s,茫崖为4.3m/s.年变化曲线型式大致相同,为单峰型变化,最大值出现在春季或夏季,最小值出现在冬季.风速频率主要分布在2 ～4m/s之间,呈铃型分布,最大值出现在一个风速非零的位置,风速变大或变小频率逐渐减小;峰值出现的风速段略有差异,黄瓜梁出现在2m/s处,茫崖出现在3m/s处.     

冀东地区重污染天气及其气象特征分析

利用2013—2015年唐山、秦皇岛环境与气象观测资料,对冀东地区冬半年重污染天气及气象特征进行分析。结果表明:重污染天气呈现西部多于东部,山区和沿海略少的分布特征;地面气象要素分析表明,重污染天气与优良天气相比,日均气压低4 h Pa,日均相对湿度高30%。重污染天气下以静风和小风为主,风速小于2.0 m/s的占71.8%;平均风速大于2.0 m/s且持续3~4 h的大风对重污染天气消散有主要作用,弱降水或短时降水对重污染天气的消散作用不明显。     

瓦里关地区大气浑浊度的观测与分析

利用瓦里关地区19949年9月－2000年9月太阳直接辐的分光观测资料,分析了该地区大气浑浊度系数的特征,并对1999年4月4次大风和扬沙过程的载尘尘量进行了估算。结果表明：（1）瓦里关地区大气浑浊系数的年平均值为0．047,波长指数平均值为4．673;大气浑浊度系数的季节变化明显,但日变化不明显。（2）大气浑浊度系数与地面风向、风速有密切关系：1999年N风时大气浑浊度系数最大,NW风次之,而SE风时大气浑浊度系数最小。≥5．0m/s的风速对大气浑浊系数的变化影响最大。（3）该地区大气相当洁净,受人类活动的影响较小,其大气浑浊度状况与同期五道染地区同属一个量级。     

廊坊市不同等级霾日气象条件异同特征分析

利用2013～2015年廊坊市气象站霾、气温、相对湿度、气压、风速、降水、日照等地面观测资料以及环保局PM2. 5资料,对各级霾的季、日气象要素特征进行了深入研究,结果表明:(1)廊坊市各级霾均有明显的季节性分布特征,轻微霾以夏季为最多,轻度、中度霾以秋季为最多,重度霾以冬季为最多;(2)重度霾的日平均气温接近相应季节的季平均值,轻微及中度霾则与季平均气温相差较大,轻度霾与季平均气温相差最大;(3)各级别霾的平均相对湿度值均高于相应季平均值,且以重度霾高出平均值为最多;(4)较低的气压利于重度霾的形成;(5)各级别霾日平均风速均小于同季平均风速,以重度霾偏小最多;(6)随着霾级别加重,日照时数明显减少;(7)各级别霾日中无降水日占比最多,表明降水可以抑制霾的形成。     

潍坊城区大气甲烷浓度变化特征

为研究城区近地面CH_4浓度特征,于2015年在潍坊市开展了CH_4连续观测实验,分析了地面风向、风速对CH_4浓度的影响。结果表明,2015年潍坊城区CH_4浓度均值为1.411 mg/m~3,季节变化特征表现为冬季高、夏季低,月均浓度分布在0.872~1.788 mg/m~3之间;日变化呈现出单峰型形态,凌晨高、下午低;偏西和偏南风向上,地面风速越大,CH_4浓度越高,在偏东风向上,CH_4浓度随风速增大而减小。     

深圳大气污染特征模拟及环境容量估算

本文根据深圳市8 个监测站点2013 年的逐日PM₁₀ 和PM_2.5 浓度监测数据、气象数据,统计风向、风速、稳定度联合频率等,利用污染物在大气中输送扩散模式,由实测的浓度值反推出污染物的产生量或排放量的方法,重点分析龙华新区PM₁₀ 和PM_2.5 的污染特征,并依据环境目标值,估算该区域剩余环境容量。研究结果表明,龙华新区全年盛行东风、南风,其风频分别为16.7%、13.2%,风速约为1.6m/s,PM₁₀、PM_2.5 浓度均呈现出季节性变化,秋、冬季浓度值较高,尤其在10 月到次年1 月份,其排放强度主要受本地污染源的影响。除此以外,其西、北部的污染源对其污染物浓度有一定的影响。新区PM₁₀ 和PM_2.5 的剩余环境容量均呈现负值,尤其以PM_2.5 最为突出,须大力加强减排控制,以达到环境目标值     

气象因子对我国西北5城市API的影响

依据2001年～2012年的空气污染指数(API)日报数据,研究西北5城市(西宁、兰州、银川、西安和乌鲁木齐)API的变化特征,同时与气象资料进行相关性分析。统计分析结果表明:(1)西北5城市首要污染物以可吸入颗粒物为主,空气质量等级以Ⅱ级良为主,日数为2 454～3 292d,比例在56.1%～75.2%。(2)5城市API指数变化规律有明显的时间和空间差异。从多年API年均值来看,西安、兰州和乌鲁木齐较高,银川和西宁相对较低,而且乌鲁木齐、兰州和西宁波动较大,西安和银川变化相对比较平缓;5城市的年变化也呈现不同的变化特征,总体上夏秋季空气质量明显好于冬春季。(3)西北5城市API和主要气象因子的相关显示出不同区域差异性。API和温度、降水与能见度均呈现显著的负相关,西宁、银川和兰州API与相对湿度为显著的负相关,西安呈负相关但相关性不显著,乌鲁木齐则为显著的正相关关系。兰州、西安和乌鲁木齐API与风速为显著的负相关,西宁和银川API则与风速为显著的正相关关系。(4)采暖和沙尘天气分别是影响我国西北5城市冬春季空气质量的重要因素。     

荆门市近60年风速风向特征分析

利用1959～2018年荆门、襄阳、武汉3个国家地面气象观测站风速风向观测资料,通过数理统计、线性分析、气候倾向率等方法,对荆门地区风向风速变化特征及变化趋势等进行气候统计分析。结果表明:荆门年平均风速为2. 9m/s,与襄阳、武汉相比均偏大,地形和地势是荆门风速偏大的主要原因;荆门、襄阳、武汉风速逐年呈整体减小趋势,但均在迁站当年出现陡升现象;荆门市风速变化与城市发展具有一定的相关性,城市快速发展时期,风速呈明显减小趋势;荆门四季主导风向均为N,N出现频次秋季最高、冬季次之,春季和夏季SSW、SW风向明显增多; 1～12月最多风向均为N,各月平均风速均大于襄阳、武汉,最大3月3. 6m/s,最小6月2. 8m/s;荆门年均大风日数为16. 5d,明显高于襄阳、武汉,大风日数整体呈减少趋势,2007年之前以4. 1d/10 a的速率减少,2008年之后以3. 3d/10 a的速率减少,大风日多出现在春季,大风风向多集中在N～NNE。荆门风速较大且有稳定的盛行风向,适宜在城市周边建设风电场;中心城区常年以北风为主,适宜建设南北方向的城市风道。     

Wind power potential assessment for three buoys data collection stations in the Ionian Sea using Weibull distribution function

The present article utilizes wind measurements from three buoys data collection stations in Ionian Sea to study the wind speed and power characteristics using the Weibull shape and scale parameters. Specifically, the site dependent, annual, and monthly mean patterns of mean wind speed, Weibull parameters, frequency distribution, most probable wind speed, maximum energy carrying wind speed, wind power density and wind energy density characteristics have been analyzed. The Weibull distribution was found to represent the wind speed distribution with more than 90% accuracy, in most of the cases. Moreover, the correlation between the percentages of times the wind speed was above cut-in-speed and the measured mean wind speed for the three selected sites, as the correlation between the aforementioned percentages and the scale parameter c were examined and were found linear. At all these sites, no definite increasing or decreasing trends in annual mean wind speed values could be detective over the data reporting period. The mean values of wind speed, scale parameter, most probable wind speed, maximum energy carrying wind speed, wind power and wind energy density values showed higher values during winter time and lower in summer time in Pylos and Zakynthos. Moreover, Pylos and Zakynthos were found to be the best sites from wind power harnessing point of view.     

珠江三角洲一次探空过程风的垂直结构特征研究

应用2004 - 10月在珠江三角洲城市群(番禺)、珠江口沿岸(新垦)和乡村(清远)大气边界层观测的资料,对珠江三角洲大气边界层风的垂直结构特征进行了分析和对比.分析结果表明:受下垫面影响,城市群、乡村和珠江口沿岸的风垂直结构以及其日变化各有特点.城市热岛比较明显,系统风小时可以观测到热岛环流;珠江口沿岸夜间有明显的海...     

Air Pollution Potential: Regional Study in Argentina

/ Air pollution potential is a measure of the atmospheric conditions that are unable to transport and dilute pollutants into the air, independently of the existence of sources. This potential can be determined from two atmospheric parameters: mixing height and transport wind. In this paper a statistical analysis of the mixing height and transport wind, in order to determine the areas with high or poor atmospheric ventilation in Argentina, is presented. In order to achieve this, meteorological data registered during 1979-1982 at eight meteorological stations were used. Daily values of the maximum mixing height were calculated from observations of daily temperatures at different heights and maximum surface temperature. At the same time as the maximum mixing height, the values of the transport wind were determined from the surface windspeed and the characteristics of the ground in the surroundings of each meteorological station. The mean seasonal values for both parameters were obtained. Isopleths of the mean seasonal of the maximum mixing heights were drawn. The percentage of seasonal frequencies of poor ventilation conditions were calculated and the frequency isopleths were also drawn to determine areas with minor and major relative frequencies. It was found that the northeastern and central-eastern regions of Argentina had a high air pollution potential during the whole year. Unfavorable atmospheric ventilation conditions were also found in the central-western side of the country during the cold seasons (37.5% in autumn and 56.9% in winter). The region with the greatest atmospheric ventilation is located south of 40 degrees S, where the frequency of poor ventilation varies between 8.0% in summer and 10.8% in winter.     

南充市近十年酸雨变化特征及降水化学组成研究

依据南充市2003~2012年城区降水环境监测统计资料,分析了酸雨变化特征及降水离子化学组成。研究表明:这十年,酸雨频率平均为50.4%,2007年降雨量为最高,呈波动递减趋势变化,降水年平均pH值为4.88,呈现"低—高—低"的变化特征,城区酸雨频率和降水pH值月均值变化呈现高低交替的波动趋势。城区降水中主要阳离子成分是Ca2+,主要阴离子成分是SO2-4和NO-3。(SO2-4/NO-3)比值逐年下降,平均比值为7.82,酸雨污染类型仍以硫酸型为主;降水(NH+4+Ca2+)/(SO2-4+NO-3)和Ca2+/NH+4比值呈波动性变化,2007年分别达到最高值为6.71和50.27,除2010年比值均较低小于1外,近年来均有增加趋势,表明碱性离子缓冲能力增强了,降水酸度降低,pH值增加,但2007年pH值较低,主要与降雨量有关。综合分析,降水酸度不仅是酸性离子和碱性离子中和作用,也受其他离子浓度和降雨量、风向等气候条件、距离传输以及地形等影响。     

四川盆地西部气溶胶空间分布现状的遥感研究初报

根据连续2天卫星遥感气溶胶光学厚度(AOD,Aerosol Optical Depth)实例,2011年4月26日AOD的高值区位于成都市区附近,27日迁移至德阳中部;27日绵阳城区及其附近的AOD次高值区是由当地累积、扩散而成;高值区的迁移与大气流场和地形特征密切相关。气溶胶颗粒物不属于四川盆地之外输入;较之以往更详细地展示了当地AOD的空间分布状况。     

四川省气溶胶光学厚度时空分布特征

本文利用MODIS气溶胶光学厚度产品,建立了气溶胶光学厚度与PM10/2.5的线性关系。分析了2008年~2012年四川省的气溶胶光学厚度时空分布特征,以成都市为特例分析了2003年~2012年的气溶胶光学厚度时空分布。结果显示:气溶胶光学厚度与PM10/2.5的线性关系较高;川西高原具有较低的气溶胶光学厚度,康定、马尔康、西昌、雅安等地年均气溶胶光学厚度约0.2;四川盆地区域具有较高的气溶胶光学厚度,以成都、德阳等地为代表,年均值在0.8~1.0之间,并具有明显季节变化特征;成都市的气溶胶光学厚度时空分布具有明显的城市特点。这些时空分布的特征与四川省的工业情况、地理位置、气候条件有关。     

基于环境一号卫星的四川盆地气溶胶光学厚度精细化反演

四川盆地为中国灰霾形势较为严重的区域之一,对四川盆地大气灰霾的监测具有十分重要的意义。利用环境一号卫星数据,对能表征大气污染程度的气溶胶光学厚度进行了反演。提出了用EVI植被指数判定暗像元精细化反演气溶胶光学厚度的方法,该方法能较好地去除部分大气影响,气溶胶光学厚度反演结果与CE318的气溶胶光学厚度结果相关性较高,误差较小,具有较高的精度,反演结果满足精细化要求。反演结果表明,四川盆地内有德阳、成都、眉山和乐山4个气溶胶光学厚度高值区,该高值区呈带状分布且与四川盆地的地形密切相关。     

Location wise comparison of mixture distributions for assessment of wind power potential: A parametric study

Scientific literature discussed various types of mixture models and models derived from maximum entropy principle using short-term wind speed data for their relative assessment. The literature on suitability of these mixture models for long-term data is rarely available. However, for correct assessment of wind power potential both wind speed and wind direction are equally important. Therefore, in this paper, both wind speed and wind direction are simultaneously analyzed using several types of mixture distribution and compared the same with conventional Weibull distribution. For wind speed and wind power density assessment, the mixture distributions such as Weibull--Weibull distribution, Gamma--Weibull distribution, Truncated Normal--Weibull distribution, Truncated Normal--Normal distribution, proposed Truncated Normal--Gamma distribution and Gamma--Gamma distribution along with MEP-distribution are compared with conventional 2-parameter Weibull distribution. Similarly, for wind direction analysis, the finite mixtures of von-Mises distribution are compared with conventional von-Mises distribution. Judgment criteria include R², RMSE, Kolmogorov--Smirnov test and relative percentage error in wind power density. The sites selected are the three onshore locations of India, viz., Calcutta, Trivandrum, and Ahmedabad. The results show that for wind speed assessment, mixture distribution performs better than the conventional Weibull distribution for analyzing wind power density. However, location wise comparison of all mixture distribution is of prime importance. For wind direction analysis, finite mixture of two von-Mises distributions proved to be a suitable candidate for Indian climatology.     

A novel wind speed forecasting model for wind farms of Northwest China

Wind resources are becoming increasingly significant due to their clean and renewable characteristics, and the integration of wind power into existing electricity systems is imminent. To maintain a stable power supply system that takes into account the stochastic nature of wind speed, accurate wind speed forecasting is pivotal. However, no single model can be applied to all cases. Recent studies show that wind speed forecasting errors are approximately 25% to 40% in Chinese wind farms. Presently, hybrid wind speed forecasting models are widely used and have been verified to perform better than conventional single forecasting models, not only in short-term wind speed forecasting but also in long-term forecasting. In this paper, a hybrid forecasting model is developed, the Similar Coefficient Sum (SCS) and Hermite Interpolation are exploited to process the original wind speed data, and the SVM model whose parameters are tuned by an artificial intelligence model is built to make forecast. The results of case studies show that the MAPE value of the hybrid model varies from 22.96% to 28.87 %, and the MAE value varies from 0.47 m/s to 1.30 m/s. Generally, Sign test, Wilcoxon’s Signed-Rank test, and Morgan--Granger--Newbold test tell us that the proposed model is different from the compared models.